The hydrogen bond energy on mismatched base pair formation between uracil derivatives and guanine in the gas phase and in the aqueous phase

Abstract

The substitution effect on hydrogen bond energies of the mismatched base pairs between some uracil derivatives (U X) and guanine (G) was studied in molecular orbital theory (MP2/6-31G ∗//HF/6-31G ∗ level). The substituent effect of U X on G–U X mismatched base pair formation energy was small, though the base pair formation energy between adenine (A) and U X, which is a normal type of the Watson–Crick type base pair, was enforced by 1.5 kcal/mol upon introducing an electron-withdrawing group (EWG) into U. Thus, U X having EWG is more likely to selectively form a base pair with A. Namely, introduction of EWG does not change selectivity of the Watson–Crick type base pair formation of U.